It means the motion you measure for something depends on where you measure from. For example, You are on the sidewalk and measure the speed of a truck and its driver to be 60mph. But if you were in the truck and measured the speed of the driver it would be zero, because now, relative to you, the driver is not moving.
a body is said to be at rest if it does not change its position relative to a reference frame similarly a body is said to be in motion if it changes its position relative to any reference frame.
Relative motion
An object is in motion if it changes position relative to a reference point. Motion is a relative quantity and is expressed in respect to the position of another object. Example: both a car and the Earth are moving (earth is revolving around the sun) but if we express the motion of the car in respect to the Earth, we say the car is moving relative to the Earth. At the same time the earth is moving relative to the sun.
Relative motion is the concept that the motion of all objects is relative to other objects. If you are sitting still right now you are not moving relative to the earth, however you are moving relative to sun.
When considering how 'fast' something is moving on earth, you ignore the fact that the earth itself is rotating, that the earth is orbiting the sun, and that the solar system itself is moving through the universe. All you care about is the relative motion between the object, and the earth itself, or another object perhaps.
At rest and in motion are relative terms. When we say 'in motion' or 'at rest' we mean relative to something else. If you were travelling in a car for instance, you would be at rest relative to the car but in motion relative to the outside world.
When its position is changing relative to our position. Note: all motion is relative to something else.
a body is said to be at rest if it does not change its position relative to a reference frame similarly a body is said to be in motion if it changes its position relative to any reference frame.
Relative motion
Relative motion
An object is in motion if it changes position relative to a reference point. Motion is a relative quantity and is expressed in respect to the position of another object. Example: both a car and the Earth are moving (earth is revolving around the sun) but if we express the motion of the car in respect to the Earth, we say the car is moving relative to the Earth. At the same time the earth is moving relative to the sun.
Motion is relative to an observer's frame of Reference.
Relative motion is the concept that the motion of all objects is relative to other objects. If you are sitting still right now you are not moving relative to the earth, however you are moving relative to sun.
When considering how 'fast' something is moving on earth, you ignore the fact that the earth itself is rotating, that the earth is orbiting the sun, and that the solar system itself is moving through the universe. All you care about is the relative motion between the object, and the earth itself, or another object perhaps.
If we're in the realm of newtonian physics I would say that it couldn't be in motion relative to a reference point, of course quantum physics and seems to prove everything we believe wrong.
motion is realtive